I don't know about those, since they are not true Sultans. They are crossbred at some point to introduce the solid black coloration, so it would depend very much on the other breed used. There is one seller on Ebay who claims to produce blue and black Sultans 'one feather at a time' from breeding whites with odd colored feathers. That doesn't say much for the quality of his original stock if this is the case, and by the looks of them they are either mixed breed or such poor examples that they don't bear much resemblance to a Sultan.
I don't know if the temperament issue is related to Sultans in general (ie. even in Turkey), or specifically hatchery stock. Because they are rare the gene pool is fairly small in the US, and it may be the result of inbreeding.
I don't know if the temperament issue is related to Sultans in general (ie. even in Turkey), or specifically hatchery stock. Because they are rare the gene pool is fairly small in the US, and it may be the result of inbreeding.